Wireless headphones, for when adjusting cords is both inconvenient and unsafe

I'm not a huge fan of listening to music while I ride, but when I do, on lonesome stretches of road or trail, I use JayBird Gear's Bluetooth-equipped Freedom earbuds. They stay in place, and, because they're wireless, I never have to stop to make adjustments (or, worse, and adjust on the fly). They’re also a good pick for runners, though jostling can make the connection choppy when the batteries near their six-hour limit. As with all Bluetooth-enabled headphones, the sound quality isn't top-notch, but if you get the fit right (there are multiple tip sizes, and wetting them helps), they’ll bring out enough bass to keep most listeners happy. Volume controlls are on the right earpiece, and I've found that a pair of Slipstreamz ($25), which are a bit like spoilers for your ears, reduce wind noise and let you hear approaching cars.